A build-over agreement is a legal contract between a property owner and a water or sewerage company. This agreement allows the property owner to construct over or within 3 metres of a public sewer or within 1 metre of a public lateral drain.
As a property owner, you may need a build-over agreement to extend your home or maximise the use of your land.
In this article, we explain everything you need to know about build-over agreements, including how to handle retrospective planning if you’ve already started building without permission from your WaSC.
A build-over agreement is needed to protect the functionality of public sewers and drains.
The main reasons they are needed include:
Build-over agreements help protect both the public sewer system and property owners. They prevent potential legal or financial issues that might arise from sewer damage.
You’ll typically need a build-over agreement if:
You’ll only need a build-over agreement for construction works affecting public drains and sewage infrastructure. If you’re unsure where the sewers or drains are on your property, you can read our article ‘How to find the drains on my property’ or book in for a CCTV drain survey.
If you have already started building over a public drain or sewer without realising that you need a build-over agreement, a retrospective build-over agreement is sometimes possible, but please keep in mind that this may not always be granted.
Complications with retrospective build-over agreements include the fact that they are:
When purchasing a property that has had work done over a public sewer or drain, you must ensure there is clear documentation on its build-over agreement.
It's possible to purchase a property that has had work done over a public sewer or drain without a build-over agreement, but it does carry some risk, so please seek legal advice.
The earlier you can get a retrospective build over agreement, the better.
If you’re looking to purchase a new-build property, our ‘Drainage guide: new builds’ will inform you of the unique conditions you can expect to find, so you can reflect on them before you make a purchase.
You cannot build over a public sewer if the water authority decides that it would make access too limited or risky. It also won’t be granted if your structure could endanger the safety or integrity of the public sewer system.
You generally can't build if:
Get one step closer to applying for a build-over agreement by following these five simple steps.
To build over a drain, you need to contact the Water and Sewage Company (WaSC) responsible for it. You can reach them through their online contact form, by phone, or via email.
If you're unsure which water or sewage company is responsible for your sewer drain, you can find this information in our article ‘How do I find out who supplies my water?’.
Your WaSC will usually ask you for detailed information regarding:
Submit your water company's build-over application form either online or by post. Your application may also require you to pay a processing fee.
The build-over agreement application can take a couple of months before you receive a final decision. Once your application has been reviewed, they may request additional information or require changes to your design.
If your application is approved, you'll receive a formal build-to-suit agreement, which means that you can legally start or proceed with your construction.
If your application is denied, you can ask for detailed feedback as to why, but you must not begin building and will likely have to remove any work already started.
At Lanes, we can carry out all of the necessary CCTV drain surveys needed for your build-over application.
Discover why the National CCTV Centre has a culture of excellence in our article ‘National CCTV Centre Achieves Latest ‘Phenomenal’ Milestone’.
Or contact us today to find out how we can help you with any sewer or drain maintenance or emergency.